Chapter 7C

Branch

A condition whose results provide transitions to different activity paths (diamond )

Activity:

Action that must take place for a process to be completed

Activity

Behavior that an object carries out while in a particular state (rounded rectangle )

Business Process Modeling Notation (BPMN):

Business process modeling approach established by the Object Modeling Group

Synchronous message:

Caller has to wait for the receiving object to finish executing the called operation before it can resume execution itself

DFDs:

Data flow, data store, source/sink, process Depicts the movement of data between external entities and the processes and data stores within a system • Show which processes move and transform data • Show which elements are inside/outside the system

Gateway:

Decision point

Activity Diagram Purpose

Depicts the flow of control from activity to activity • Help in "use case" analysis to understand what actions need to take place • Help in identifying extensions to a "use case" • Model work flow and business processes • Model the sequential and concurrent steps in a computation process

Sequence Diagrams

Depicts the interactions among objects during a certain period of time • May be presented in either generic form or instance form: • Generic form: Shows all possible sequences of interactions, corresponding to all scenarios of a use case • Instance form: Shows the sequence for only one scenario

Message:

Means by which objects communicate with each other

Objects:

Represented by boxes at top of diagram

Asynchronous message:

Sender does not have to wait for the recipient to handle the message

Sequence diagrams:

Show explicit sequencing of messages

Collaboration diagrams:

Show relationships among objects

Generic form:

Shows all possible sequences of interactions, corresponding to all scenarios of a use case

Instance form:

Shows the sequence for only one scenario

Flow:

Shows the sequence of action in a process

Business Process:

Standard method for accomplishing a particular task necessary for an organization to function

Elements of Activity Diagrams: A user wants to logon to a system

Start: The beginning of a process (filled in circle ) • Branch: A condition whose results provide transitions to different activity paths (diamond ) • Activity: Behavior that an object carries out while in a particular state (rounded rectangle ) • Merge: Where different paths converge (diamond ) • End: The end of a process (a filled in circle that has another circle around it )

Elements of Activity Diagrams: Customer Ordering Process

Swimlanes: Columns representing different organizational units of the system (vertical lines) Start: The beginning of a process (filled in circle) Activity: Behavior that an object carries out while in a particular state (rounded rectangle) Fork: Beginning of parallel activities (horizontal line with 2 arrows coming out of it) Branch: A condition whose results provide transitions to different activity paths (diamond) Merge: Where different paths converge (diamond) Join: End of parallel activities (horizontal line with 2 arrows coming into it) End: The end of a process (a filled in circle that has another circle around it)

Start

The beginning of a process (filled in circle )

End:

The end of a process (a filled in circle that has another circle around it )

Lifeline:

Time during which an object exists

Activation:

Time period during which an object performs an operation

• Simple message:

Transfers control from the sender to the recipient without describing the details of the communication

• Event:

Trigger that initiates the start of a process

Use case diagrams:

Use case, actor, connection, system boundary Show a system's available top-level functions for different types of users • Depicts system behavior along with the key actors that interact with the system

Merge:

Where different paths converge (diamond )

DFDs vs. Use Case Diagrams

• Elements: • DFDs: Data flow, data store, source/sink, process • Use case diagrams: Use case, actor, connection, system boundary • • DFDs: • Depicts the movement of data between external entities and the processes and data stores within a system • Show which processes move and transform data • Show which elements are inside/outside the system • Use case diagrams: • Show a system's available top-level functions for different types of users • Depicts system behavior along with the key actors that interact with the system

Activity Diagrams

• Show the conditional logic for the sequence of system activities needed to accomplish a business process •Clearly show parallel and alternative behaviors •Can be used to show the logic of a use case •What does an Activity Diagram look like?

Specialized Notation

• Specialized event notation (such as from message, or at particular time) • Specialized flow notation (sequence, default, or message flow)

Types of Messages

• Synchronous message: Caller has to wait for the receiving object to finish executing the called operation before it can resume execution itself • Simple message: Transfers control from the sender to the recipient without describing the details of the communication •Asynchronous message: Sender does not have to wait for the recipient to handle the message

Types of BPMN Gateways

• XOR: Exclusive OR gateway; only one of the paths that exit the gateway can be followed •AND: All of the paths that follow the gateway can be followed in parallel •OR: At least one path out of the gateway must be followed, but all paths that leave the gateway can be followed

Interaction Diagrams

•Used to show interactions among objects for a particular use case • Two types of interaction diagrams: • Sequence diagrams: Show explicit sequencing of messages • Collaboration diagrams: Show relationships among objects